One of the key drivers of Christianization was the work of missionaries. These devout men and women, often monks or priests, traveled to remote and pagan areas to spread the Christian faith. Some of the most famous include:

• Saint Patrick, who converted much of Ireland in the 5th century.
   

• Saint Augustine of Canterbury, who was sent by Pope Gregory the Great in 597 to convert the Anglo-Saxons in England.
   

• Saint Boniface, known as the "Apostle to the Germans," who brought Christianity to parts of modern-day Germany in the 8th century.
   

• Saint Cyril and Saint Methodius, who translated the Bible into Slavic languages and converted many in Eastern Europe.
   

These missionaries often began by converting local leaders or kings. Once a ruler converted, his people typically followed — whether through genuine belief or political necessity. This strategy of "top-down" conversion was especially effective. For example, when King Clovis I of the Franks converted to Christianity around 496 AD, it marked the beginning of France as a Christian kingdom. Similar conversions occurred in Scandinavia, Eastern Europe, and the Slavic world over the following centuries.

  Political Power and Religious Legitimacy

Christianity also became a tool of political power. Rulers who embraced the faith could claim divine legitimacy. The idea of the "divine right of kings" — that monarchs ruled by God’s will — was reinforced by Christian theology. Kings who supported the Church were often supported in return. This symbiotic relationship gave both Church and state more authority.

The most famous example of this is Charlemagne, king of the Franks and later Holy Roman Emperor. In 800 AD, Pope Leo III crowned Charlemagne as Emperor of the Romans. This event symbolized the fusion of Christian and imperial authority and created a model for Christian kingship that would influence Europe for centuries.

Even in Eastern Europe, Christian rulers used religion to strengthen their rule. When Vladimir the Great of Kievan Rus converted to Christianity in 988 AD, he aligned his realm with the Byzantine Empire and used religion to consolidate power over his diverse subjects. shutdown123